OBD Guide

P1400

Differential Pressure Feedback Electronic Sensor Circuit Low Voltage

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$17–56 (est.)

Symptoms

  • Check Engine Light Is On
  • Reduced engine power
  • Unstable idling
  • Increased fuel consumption
  • Dips during acceleration

Causes

  • EGR differential pressure sensor malfunction
  • Open or short circuit in the sensor circuit
  • Poor contact in the sensor connector
  • Wiring Harness Problems
  • Engine control unit malfunction

How to Fix

  1. Check the integrity of wiring and connectors
  2. Measure resistance and voltage at the sensor
  3. Check the operation of the EGR valve
  4. Replace differential pressure sensor if necessary
  5. Clean or replace the EGR valve if dirty

Related codes

Error P1400 by Vehicle Brand